diff options
| author | Qu Wenruo <quwenruo@cn.fujitsu.com> | 2014-01-06 09:58:25 +0800 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-01-28 13:20:16 -0800 |
| commit | 842bef5891aaf13e2dede01d86397d810fde2dd8 (patch) | |
| tree | 33b072d33c9c2479cf78e0fdc31bb8be03985349 | |
| parent | e8117c26b24098496b6011aabe84e43e0189a506 (diff) | |
btrfs: Add "barrier" option to support "-o remount,barrier"
Btrfs can be remounted without barrier, but there is no "barrier" option
so nobody can remount btrfs back with barrier on. Only umount and
mount again can re-enable barrier.(Quite awkward)
Also the mount options in the document is also changed slightly for the
further pairing options changes.
Reported-by: Daniel Blueman <daniel@quora.org>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Mike Fleetwood <mike.fleetwood@googlemail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
| -rw-r--r-- | Documentation/filesystems/btrfs.txt | 13 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 8 |
2 files changed, 14 insertions, 7 deletions
diff --git a/Documentation/filesystems/btrfs.txt b/Documentation/filesystems/btrfs.txt index 5dd282dda55..ce487a2a88f 100644 --- a/Documentation/filesystems/btrfs.txt +++ b/Documentation/filesystems/btrfs.txt @@ -38,7 +38,7 @@ Mount Options ============= When mounting a btrfs filesystem, the following option are accepted. -Unless otherwise specified, all options default to off. +Options with (*) are default options and will not show in the mount options. alloc_start=<bytes> Debugging option to force all block allocations above a certain @@ -138,12 +138,13 @@ Unless otherwise specified, all options default to off. Disable support for Posix Access Control Lists (ACLs). See the acl(5) manual page for more information about ACLs. + barrier(*) nobarrier - Disables the use of block layer write barriers. Write barriers ensure - that certain IOs make it through the device cache and are on persistent - storage. If used on a device with a volatile (non-battery-backed) - write-back cache, this option will lead to filesystem corruption on a - system crash or power loss. + Enable/disable the use of block layer write barriers. Write barriers + ensure that certain IOs make it through the device cache and are on + persistent storage. If disabled on a device with a volatile + (non-battery-backed) write-back cache, nobarrier option will lead to + filesystem corruption on a system crash or power loss. nodatacow Disable data copy-on-write for newly created files. Implies nodatasum, diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 15b6a1d4c53..b02d25a64b2 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -323,7 +323,7 @@ enum { Opt_no_space_cache, Opt_recovery, Opt_skip_balance, Opt_check_integrity, Opt_check_integrity_including_extent_data, Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree, - Opt_commit_interval, + Opt_commit_interval, Opt_barrier, Opt_err, }; @@ -335,6 +335,7 @@ static match_table_t tokens = { {Opt_nodatasum, "nodatasum"}, {Opt_nodatacow, "nodatacow"}, {Opt_nobarrier, "nobarrier"}, + {Opt_barrier, "barrier"}, {Opt_max_inline, "max_inline=%s"}, {Opt_alloc_start, "alloc_start=%s"}, {Opt_thread_pool, "thread_pool=%d"}, @@ -494,6 +495,11 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) btrfs_clear_opt(info->mount_opt, SSD); btrfs_clear_opt(info->mount_opt, SSD_SPREAD); break; + case Opt_barrier: + if (btrfs_test_opt(root, NOBARRIER)) + btrfs_info(root->fs_info, "turning on barriers"); + btrfs_clear_opt(info->mount_opt, NOBARRIER); + break; case Opt_nobarrier: btrfs_info(root->fs_info, "turning off barriers"); btrfs_set_opt(info->mount_opt, NOBARRIER); |